This invention relates generally to backup and restore of file systems, and in particular to storage efficient backup.
File systems provide permanent storage for data that is critical to an organization. Therefore, file systems form an important part of an organization's information technology. File systems are used for persistent storage of data by applications used in an organization, for example, email servers, document management systems, source code management systems and the like. Organizations make copies of the data stored in the file systems to avoid loss of data in case the original data in the file system is destroyed or corrupted. The process of making copies of the data is called a backup. Conventional systems that perform backups of data store the data in storage devices with large storage capacity, for example, magnetic tapes. These devices typically have slow access time. Conventional systems restore data from the backup storage in case of loss of data stored in the original file system. The process of restoring data of a large file system can take significant amount of time resulting in loss of business during the time the data is unavailable.